Method of manufacturing thinwalled shaped bodies



Patented Jan. 7, 1936 v H t UNITED STATES PATENT OFFICE METHOD OF MANUFACTURING THIN- WALLED SHAPED BODIES Eugen Heinlein, Berlin, Germany No Drawing. Application October 7, 1933, Serial No. 692,617. In Germany October 13, 1932 1 Claim. (01. 25155) For manufacturing shaped bodies of concrete crete in the mould by a die, as is more fully dethere are known methods in which the earthscribed hereinafter. moist mass is blown by compressed air from out In order to make matters completely clear I of the receptacle containing that mass into am describing here the manufacture of flower 5 moulds pressed directly against that receptacle. pots of concrete according to my improved 5 It has, however, been found that when making method: unusually large quantities of thin-walled shaped The pots are blown into a mould consisting of bodies, as, for instance, flower pots, drawbacks a shell and a core. Up to now it has been necesarise from the reason that the compression prosary to leave the shaped bodies in the mould (that duced by the air-pressure in the mould is not is to say, either in the shell or on the core, in 10 strong enough to allow of immediately putting that one of these members is removed after the aside the blown bodies without providing any blowing) for a period of time of about 10 hours special means for supporting the shaped bodies. or more until the binding of the mass had pm- It is, in fact, necessary that the mass, 1. e. the ceeded far enough to allow of removing also the concrete or, may be, cement, first binds within other part of the mould. In my improved method 15 the mould which requires a period of time of the moulds are filled and the mass is blown in about 10 hours or even more before the blown the same manner as heretofore whereafter the article can be removed from the mould, in consecore of the mould is removed, the shaped body quence whereof that known method which is inbeing now held solely by the mould shell. In this tended especially for wholesale manufacture restate the mould shell with the shaped body in it 20 quires an enormous number of moulds. is conveyed to a rotatory die which is a little larger Besides, the compression obtained solely by than the removed mould core. The die is now means of the compressed air is in certain cases introduced into the shaped body and pressed onto not sufficient to bring about the requisite permethe same so strongly that the mass is correspondability to water of the shaped bodies or, as reingly compressed and rendered dense to such a 25 gards particularly thin-walled shaped bodies, the degree that the not yet bounded shaped body can requisite tensile strength after the binding of the be removed at once from the core too.

concrete or cement. In cases in which the concrete or cement body The before-mentioned drawbacks are overis not of conical shape, the after-Pressing and come, according to the present invention, by sub- -compressing is effected with the aid of a station- 30 jecting the concrete or cement blown into the ary die. mould, prior to its getting bound, to the action It is suited to the purpose in View either to irriof an either stationary or rotatory die, by which, gate with water or to dust with pure cement the after a mould part has been removed, the shaped mass that has been filled into the mould, but not body or article is subjected to an after-pressing yet been subjected to the after-pressing, where- 35 procedure and a separate compression. another increase of the density and the strength I am aware of the fact that it is no more new of the finished article is obtained.

to produce concrete bodies by shaping them with I claim:

the aid of a die and employing this latter for The method of manufacturing particularly 4O compressing the mass, but that procedure can thin-walled shaped bodies of earth-moist masses be carried out only with pulpy masses, the excess not able to flow, for instance concrete and ceof the individual portions of which protrudes m t, in m ulds Consisting of w p t Sa d forth from the mould and is then stripped off. method compr blowing the mass into the Another known procedure is that in which a plasmould, removing one of the mould parts, subjecttic mass like clay or the like is pressed by means ing the mass in the remaining mOuld p o the 45 of a die for manufacturing flower pots and other action of a die so as to subject it to an after-presshollow bodies. In contradistinction to all that me and mpr ine, the Strength of which i o the gist of the present improved method consists chosen that also the other mould part can be in the combination of the blowing procedure, in removed prior to the mass having set.

which the earth-moist concrete is blown into a 50 closed mould, with the compression of the con- EUGEN HEINLEIN. 

